The present invention relates to dispensing closures incorporating a self-closing valve, for use with squeeze-type containers, such as flexible bottles or tubes. The valve is adapted to open when the container is squeezed, to allow product to be dispensed and thereafter, once the container is released, the valve closes automatically. In particular, the invention relates to dispensing closures of this type which include a built-in seal to seal the valve and prevent accidental spillage of the contents of the container during transportation or storage.
Dispensing closures incorporating a self-closing valve are becoming more popular as after first opening by a user, the container may be stored and used without the need to open and close a separate lid. The valve ensures that the contents of the container will not leak even when the container is inverted. Such closures are therefore ideal for use with personal care products, such as shampoo and shower gel or foodstuffs, such as tomato ketchup and sauces.
A typical closure includes a flexible, self-closing valve arranged to cover the opening in a container. The valve is provided with one or more slits which define a normally closed orifice. When a user squeezes the container, the increased pressure within the container causes the orifice to open and the contents of the container are thereby dispensed. A common form of self-closing valve has two slits in a cross configuration to define four flaps, which are normally closed. When the container is squeezed, the flaps open to provide an orifice through which the contents of the container may be dispensed.
A typical dispensing closure incorporating a self-sealing valve comprises a body, arranged to co-operate with a container neck, the body defining a seat for the self-closing valve. The valve is held in place in the seat by a clip or retaining ring. The closure may also be provided with a lid to cover the valve during transportation and storage. The lid ensures that the valve remains clean and is not damaged before it reaches the consumer. Many closure designs incorporate a hinged lid, which is produced integrally with the body. Sometimes, the lid is provided with a projection, which is sized and arranged to co-operate with the closed valve and prevent it from opening when the lid is closed. This arrangement ensures that the contents of the container are not accidentally dispensed into the cavity between the closure body and the lid.
The disadvantage of such dispensing closures is that a lid or cover of some sort has to be provided covering the valve, to prevent leakage of the container contents during transportation or storage. The consumer does not need to use the lid after first opening, and it can hinder satisfactory use of the package. Furthermore, even with a lid, the contents of the container may seep into the cavity between the lid and the valve necessitating a requirement for a valve engagement projection as previously described. However, the provision of a projection makes the closure more difficult to manufacture. Finally, there may be circumstances where it is desirable to prevent contact between the container contents and the self-closing valve material during transportation and storage. Some products may have a deleterious effect on the valve material over time, which hinders the proper functioning of the valve.
A solution to these problems is proposed in the published PCT application WO97/22530. The proposed closure comprises a body, adapted to co-operate with a container opening, and a housing, which can be raised and lowered relative to the body using either a twisting or push-pull movement. The housing provides a seat for the dispensing valve, as in the conventional closures previously discussed, but also has a sealing plug located below the level of the valve, between the valve and the container opening. The closure body provides a sealing ring around the container opening. The sealing plug in the housing forms a seal with the sealing ring in the closure body, when the housing is in its lowered position, preventing leakage of the container contents. Thus, the valve is sealed inside the closure rather than by means of an external cover or lid. The sealing plug and sealing ring arrangement ensures that the container contents are prevented from coming into contact with the valve during transportation and storage of the package.
One of the disadvantages of this arrangement is that it is complicated and therefore difficult to manufacture and assemble. The design is based on the conventional valve dispensing closure with the addition of a separate sealing arrangement located inside the closure, in the dispensing passageway. As in the conventional valve dispensing closure, the valve requires a valve seat in the housing component with a retaining ring or clip to hold it in place. Furthermore, the housing component is more complicated as it also has to provide a sealing plug for the transport/storage seal. This arrangement relies on accurate alignment between the sealing plug and the sealing ring on the body to provide a satisfactory seal.
The applicants have found that a much simpler sealing arrangement can be provided inside the closure, in the dispensing passageway, requiring fewer components and less accurate alignment. The closure according to the invention is therefore, simpler and easier to manufacture and assemble than the closure proposed in WO97/22520.
The present invention provides a simplified closure having a dispensing valve and a transport/storage seal inside the closure within the dispensing passageway. The transport/storage seal is arranged so that the container/closure package can be sealed or unsealed by either twisting or push-pull movement of the outside of the closure by the user.
Accordingly the present invention provides a closure for a container opening, the closure comprising a housing, adapted to co-operate with the container opening and defining a dispensing passageway; a cover disposed on the housing for movement between lowered and raised positions relative to the housing; and a flexible dispensing valve, characterised in that the housing provides a sealing plate located, in use, between the dispensing valve and the container opening; the sealing plate adapted to partially occlude the container opening and defining at least one dispensing aperture; and the dispensing valve is arranged to seal the or all of the dispensing apertures when the cover is in its lowered position.
In the arrangement according to the invention, the dispensing valve is used to provide the xe2x80x9csealing plugxe2x80x9d to block the dispensing apertures in the sealing plate during transportation and storage of the package. Thus, a separate sealing plug is not required, simplifying the design. Furthermore, due to the flexibility of the valve, it is able to conform to the contour of the dispensing aperture/s and therefore forms a good seal.
Advantageously, the valve and sealing plate are arranged in fixed orientation relative to one another within the housing and the housing is fixed in relation to the container opening. This arrangement has the advantage that a moving seal is not required between the cover and the housing.
In one such embodiment of the invention, the cover is adapted to press against part of the valve as the cover is lowered. This stretches part of the valve, so that it blocks the dispensing aperture or apertures and the lowered cover holds the stretched portion of the valve in place to ensure that the seal is retained. When the cover is raised, the natural elasticity of the valve material returns the valve to its original relaxed configuration and the contents of the container are able to pass through the dispensing apertures. Preferably an annular projection is provided on the internal surface of the cover. The projection is arranged to co-operate with the periphery of the dispensing valve and thereby stretch this portion of the valve. The dispensing apertures are arranged around the periphery of the sealing plate such that they are sealed by the stretched portion of the dispensing valve when the cover is in its lowered position.
The valve may be retained in a seat in the housing by a retaining ring or clip, as in the conventional dispensing valve closures. However, it will be apparent that the annular projection from the cover, may be configured to ensure that the valve is retained in the seat when the cover is in its raised and lowered positions. This arrangement removes the need for a separate retaining ring or clip and thereby further simplifies the design and assembly of the closure.
Alternatively, the cover may be adapted to press part of the valve against the dispensing aperture/s when it is in its lowered position, without stretching the valve. When the cover is raised, the valve remains covering the dispensing apertures but is no longer held in place by the cover. When a user squeezes the container, the internal pressure within the container forces the valve away from the dispensing apertures, thereby allowing the product in the container to be dispensed through the dispensing apertures and the valve orifice. After dispensing the product, the valve will naturally retract back against the sealing plate, due to the partial vacuum in the container.
In another embodiment of the invention, which is particularly suited for use with tubes, the housing forms one end of a tube or container and is an integral part thereof. The cover is located over the housing end of the tube. The tube or container is filled from the end furthest from the closure, in the conventional manner. This further simplifies the construction of the container/closure assembly.
The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: